Testing general relativity using millimeter wavelength radio interferometry of Sgr A*

General relativity, though widely accepted in the weak-field limit, is difficult to test in the strong-field regime. Millimeter wavelength VLBI offers a unique opportunity to resolve the black hole structure on event-horizon scales. The ability of millimeter wavelength VLBI observations of Sgr A* to constrain black hole parameters such as mass, spin, and deviation from general relativity was considered. Realistic simulations of Sgr A* were performed using the MAPS software. Image reconstructions were made using MACIM and image-based parameter extraction using the Hough transform was considered. Non-imaging techniques using least-squares fitting of a simple ring and gaussian model to VLBI amplitudes and closure phases were considered. The Hough transform is not able to place strong constraints on black hole parameters. Least-squares fitting techniques indicate possible sensitivity to deviations from general relativity and prove able to extract the photon ring radius to within 5-7% of the expected value. It is concluded that VLBI observations of Sgr A* represent a promising opportunity for testing general relativity in the strong-field regime.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2012

Author dc:creator

• Ruprecht, Jessica Dawn

Advisor dc:contributor.advisor

• Richard P. Binzel

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/114350

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/114350